Motion of electrons in orbitals and shape of orbitals

In summary, the conversation discusses the movement of electrons within orbitals and the shape of p-orbitals. Quantum mechanics describes the true physical reality of atoms and the concepts of position and momentum are different in this context. The p-orbital is represented by a single electron with a specific magnetic quantum number, and if averaged over all possible magnetic quantum numbers, it becomes spherical. However, due to a property called intrinsic spin, an orbital can represent one or two electrons. Classical reasoning breaks down in quantum mechanics, and the notion that electrons orbit the nucleus is incorrect. The p-orbital has a dumbbell shape due to the non-zero angular momentum of the electron. This allows for the explanation of multiple bonds in chemistry.
  • #1
AudioFlux
58
0
Why don't electrons move only along the surface of orbitals?
Moreover, how do electrons move within orbitals, random movement or do they follow a definite path?
In a p-orbital, does one lobe consist of only one electron?
Why is the p-orbital dumbbell shaped and not spherical?
 
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  • #2
The true physical reality of atoms is described by Quantum Mechanics.
The concepts of position and momentum are different in quantum mechanics. Think of the position as being spread out in space. (Not technically true, but its a good way to describe it). So the electron doesn't go round in a specific path.
If you've seen a picture of the p-orbital, it likely represents a single electron, with a particular magnetic quantum number. If you average over all possible magnetic quantum numbers, then the p-orbital is spherical.
 
  • #3
BruceW said:
If you've seen a picture of the p-orbital, it likely represents a single electron, with a particular magnetic quantum number.

But doesn't each orbital represent the electron cloud of two electrons?

If you average over all possible magnetic quantum numbers, then the p-orbital is spherical.

If you average all the magnetic quantum numbers, won't you get 0?

So the electron doesn't go round in a specific path.

If the electron does not go around the nucleus in a circular path, won't it come crashing to the nucleus?
 
  • #4
AudioFlux said:
Why don't electrons move only along the surface of orbitals?
Moreover, how do electrons move within orbitals, random movement or do they follow a definite path?
In a p-orbital, does one lobe consist of only one electron?
Why is the p-orbital dumbbell shaped and not spherical?

The representation of atomic orbitals in terms of their electron densities just tells you that the majority of said electron density is mostly localized within that volume - not that the electron is bound to the surface contour that is plotted.

Strictly speaking, an orbital is a one-electron wavefunction.

To (over)simplify the discussion, an electron in a p orbital has non-zero angular momentum. When one works through the math for this case, you get the dumbbell-looking electron density.

AudioFlux said:
If the electron does not go around the nucleus in a circular path, won't it come crashing to the nucleus?

Welcome to quantum mechanics. Classical reasoning breaks down here. The notion that electrons "orbit" the nucleus is incorrect.
 
  • #5
AudioFlux said:
But doesn't each orbital represent the electron cloud of two electrons?
It can represent one or two electrons. This is due to a property of the electron called intrinsic spin.

AudioFlux said:
If you average all the magnetic quantum numbers, won't you get 0?
No, you can have an electron which is in a quantum superposition of all the possible magnetic quantum numbers for the p-orbital, and the wavefunction describing this particle will be symmetric. (not dumbell shaped.)


AudioFlux said:
If the electron does not go around the nucleus in a circular path, won't it come crashing to the nucleus?
Nope. Classical physics < Quantum physics :)
 
  • #6
"If you average over all possible magnetic quantum numbers, then the p-orbital is spherical".


Surely for a p-orbital with an orbital angular momentum quantum number of 1 the wavefunction describes a dumbell shape. In order for the wavefunction to descibe a spherical orbital the orbital angular momentum quantum number must be 0.
If a p-orbital were indeed spherical almost all of the chemistry associated with multiple bonds would be difficult to explain.
 

1. What determines the shape of an orbital?

The shape of an orbital is determined by the probability of finding an electron in a particular region of space. This probability is described by the mathematical function called the wavefunction, which is dependent on the energy of the electron and the attractive force of the nucleus.

2. How do electrons move in orbitals?

Electrons in orbitals do not move in a circular path like planets around the sun. Instead, they move in a wave-like pattern, constantly changing their position and velocity within the orbital. This is due to the wave-like nature of electrons and the uncertainty principle.

3. Why are there different types of orbitals?

The different types of orbitals (s, p, d, and f) have different shapes and orientations because they correspond to different energy levels and subshells within an atom. These different energy levels and subshells have unique properties and allow for the arrangement of electrons in a specific way, which contributes to the stability of the atom.

4. How are orbitals related to electron configuration?

Electron configuration is the arrangement of electrons in an atom's orbitals. The number and type of orbitals available for electrons to occupy is determined by the atom's energy level and the number of electrons it has. The electron configuration of an atom determines its chemical and physical properties.

5. Can an electron exist in more than one orbital at a time?

No, according to the Pauli exclusion principle, an electron can only exist in one orbital at a time. This is because each orbital can only hold a maximum of two electrons, with opposite spins. This principle helps to explain the stability and behavior of atoms and the arrangement of electrons in orbitals.

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